US3387992A

US3387992A - Process and apparatus for distributing liquids

Info

Publication number: US3387992A
Application number: US555647A
Authority: US
Inventors: James B Arthur; Neil E Lloyd
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1962-08-14
Filing date: 1966-06-02
Publication date: 1968-06-11
Anticipated expiration: 1985-06-11

Description

June 11, 1968 J. B. ARTHUR ET AL 3,387,992

PROCESS AND APPARATUS FOR DISTRIBUTING LIQUIDS 3 Sheets-Sheet 1 Original Filed Aug. 14, 1962 June 11, 1968 J. B. ARTHUR ET AL 3,387,992

PROCESS AND APPARATUS FOR DISTRIBUTING LIQUIDS 6 Sheets-Sheet Original Filed Aug. 14, 1962 Tiq. 2.

k in" OOOOOOO u i b L w June 11, 1968 J. B. ARTHUR ETAL 3,387,992

PROCESS AND APPARATUS FOR DISTRIBUTING LIQUIDS Original Filed Aug. 14, 1962 3 Sheets-Sheet 5 Unite States Patent 3,387,992 PROCESS AND APPARATUS FOR DISTREBUTING LIQUEDS James B. Arthur, Charlotte, N.C., and Neil E. Lloyd, Rock Hill, S.C., assignors to Celanese Corporation, a corporation of Delaware Qontinuation of application Ser. No. 216,894, Aug. 14, 1962. This application June 2, 1966, Ser. No. 555,647 15 (Ilaims. (til. 117-14953) ABSTRACT 6 F THE DISCLOSURE 'Process and apparatus for the application of liquid material such as plasticizer to a filamentary web preferably adapted for the preparation of cigarette filter rods, wherein centrifugal spray means providing sheets of droplets are employed, in a housing permitting liquid recycle, the operation being characterized by a projection of at least some of the liquid droplets through the tow whereby uni form application of the liquid addenda is readily and continuously achieved.

This application is a continuation of copending application Ser. No. 216,894, filed Aug. 14, 1962 and now abandoned.

This invention relates to the art of spraying liquids, and in particular to processes of and apparatus for centrifugally spraying such liquids for a variety of purposes.

The main object of the present invention is to provide centrifugal liquid-spraying processes and apparatus which may be utilized in such diverse applications as the manufacture of synthetic filaments in either continuous or staple form, the coating of filamentary or fibrous strands, webs and like materials with one or more of a number of different finishes or special .purpose compositions prior to the ultimate use of such filamentary materials, the covering of non-fibrous materials with plastic coatings, etc.

A special object of the present invention is the provision of such processes and apparatus for applying plasticizers and/ or other liquid finishes to filamentary materials either in the form of a coherent web or in the form of loose multi-filament strands such as cigarette tow.

A related object of the present invention is the provision of rotatable liquid-centrifuging means positioned adjacent the path of movement of the material, filamentary or otherwise, to be coated, in association with means for feeding the liquid to the said rotatable means.

A more specific object of the present invention is the provision of rotatable discs or similarly shaped members constructed so as to define radial fiow paths for the liquid and adapted to be positioned singly or in pairs adjacent the said path of movement of the material to be coated.

The foregoing and other objects, characteristics and advantages of the processes and apparatus according to the present invention will be more fully understood from the following detailed description thereof when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a partly schematic, vertical section through an apparatus (viewed from the front) employing a liquidspraying disc constructed in accordance with one embodiment of the present invention;

FIG. 2 is a side elevational view taken along the line 22 in FIG. '1, certain parts being omitted for the sake of clarity;

FIG. 3 is a sectional view of a slightly modified type of spraying disc which may be employed in the apparatus of FIGS. 1 and 2;

FIG. 4 is a sectional view of still another form of spraying disc according to the present invention;

.. FIG. 5 is an elevational view of the disc shown in FIG.

4, the view being taken along the line 55 in FIG. 4;

FIG. 6 is a diagrammatic illustration of a spraying disc of one of the aforesaid types employed in treating a band of filamentary material moving past the disc at one side thereof; and

FIGS. 7 and 8 are similar diagrammatic views of a dual set of such discs as employed to spray liquid on a filamentary material moving past them either at one side of or between the discs.

The processes according to the present invention are particularly well suited for use in the application of finishes to synthetic filaments spun through a multi-orifice spinnerette the construction of which is well known and per se constitutes no part of the invention herein. Preferably, the filamentary materials may comprise organic derivatives of cellulose such as the esters or ethers thereof, e.g. cellulose organic acid esters such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose benzoate, cellulose acetate formate, cellulose acetate propionate, cellulose acetate butyrate, and the like, and ethers such as ethyl cellulose, etc. The esters may be ripened and acetone-soluble, such as conventional cellulose acetate, or may be substantially fully esterified, i.e. contain fewer than 0.29 free hydroxyl groups per anhydroglucose unit, such as cellulose triacetate.

The filaments may, of course, be made of other materials of thermoplastic nature. Examples of these materials are the superpolyamides such as nylon, superpolyesters such as polyethylene terephthalate, polyglycolic acid and copolymers thereof, acrylonitrile polymers and copolymers, polymers and copolymers of olefins and vinyl esters such as ethylene, propylene, vinyl chloride, vinylidene chloride, and vinyl acetate, and the like.

One of the fields in which the processes and apparatus according to the present invention find particular application is in the manufacture of cigarette filters from synthetic continuous filaments of the aforesaid types. In the manufacture of such materials, the filaments, subsequent to their being formed, are combined into yarns or tows, i.e. strands composed of a relatively large number of individual filaments ranging from as few as ten to as many as several millions. In such continuous filament tows, the originally more or less straight filaments must be specially treated with, among other things, a plasticizer so as to ensure that the ultimate filter plugs have the desired firmness. In order to facilitate this treatment, it is customary to apply the plasticizer to the filaments by means of spray nozzles or kiss rolls after opening the tow, with the object that the plasticizer must be applied to all the lfilaments and, as nearly as possible, uniformly to the entire tow.

Referring now more particularly to FIGS. 1 and 2, an apparatus 10 is there shown which comprises a housing or cabinet 11 made of any suitable material, preferably stainless steel or the like. The housing 11 has vertical side walls 12 and 13, vertical front and rear walls 14- and 15, a floor and a ceiling. The housing floor consists of a pair of sections 15a and 16%: extending toward one another from the lowermost edges of the sidewalls 12 and 13 at a relatively gentle downward slope and terminating at a predetermined distance from one another essentially medially of the housing 11, thereby leaving an elongated rectangular opening 17 extending entirely across the housing fioor. Arranged below the opening 17 is a well 18 defined by two vertical,

trapezoidal side plates

18a and 18b depending downwardly from the facing edges of the housing fioor sections 16a and 16b, two slanted end plates 18c and 18d secured to the downwardly converging edges of the

plates

18a and 18b, and a horizontal bottom plate ISe secured to the lowermost edges of the plates 18a to 18d. The ceiling of the housing 11 is closed and consists of a pair of sections 19a and 19b extending toward 3 one another at relatively steep slopes from the uppermost edges of the side walls 12 and 13.

Within the well 18 of the housing 11, a liquid-spraying disc 20 is arranged for rotation in a plane which is substantially parallel to and centered between the well

side plates

18a and 18b. The disc 20 is essentially shaped in the manner of a cup having an imperforate back plate 21 and an annular wall 22 oriented perpendicularly to the plane of the back plate 21. The annular wall 22 is provided with a plurality of of peripherally spaced, substantially radially extending orifices or passageways 23 and with an inwardly directed annular front fiange 24 having 'an opening 25 at its center and defining an interior channel or groove 26 communicating with the inner ends of the orifices 23. The number of orifices may range from as few as 4 to as many as 24, depending on the size of the disc and the utlimate use of the liquid dis tributed or sprayed out by the disc. The diameter of each orifice preferably ranges from about 4 to about inch, although the choice of any given diameter will also depend on the same factors as the number of orifices, and for any specific spraying operation will be suitably correlated to the number of orifices.

Afiixed to the outer face of the back plate 21 of the disc 20 is an axial bushing or sleeve 27 which extends rotatably with slight clearance through an opening 28 in the well side plate 18a. The outermost end of the bushing or sleeve 27 receives and is secured for example by means of a set screw 29 or the like, to the output shaft 39 of an electric motor 31 mounted on and bolted to a platform 32 rigidly affixed to the housing 11, e.g. by being welded at 32 to the plate 18a and at 32 to the lowermost ends of a pair of angle members 33 rigidly secured, as by welding, at their uppermost ends to the door section 16a of the housing. It will be understood that the bushing 27 may be connected through the intermediary of any suitable transmission means (not shown) such as gears, sprocket chains or drive belts, to the motor 31, especially if the latter is mounted on a separate supporting structure. The entire apparatus 10 may be rendered portable with the aid of a table mounted on rollers and supporting the housing 11 and the motor 31, as well as other instrumentalities still to be described.

The other side plate 18b of the well 18 is provided with two openings in one of which is mounted a sight glass plug or window 34 through which the operation of the disc 20 can be observed. A short length of externally threaded pipe 35 extends through the other opening, coaxially with the disc, and carries a pair of locking nuts 36 and 37 at the opposite faces of the plate 1%. Connected to the pipe 35 interiorily of the well 18 is a nozzle structure 38 the discharge portion 38a of which is oriented substantially at right angles to the axis of the pipe 35. Thus, it will be clear that the pipe 35 and nozzle structure 38 may be adjusted toward and away from the disc 20, with the nuts 36 and 37 serving to lock the nozzle structure in position.

Exteriorly of the well 18, the pipe 35 communicates with a liquid supply or feed pipe 39 which communicates with the pressure side of a metering pump 40 of any suitable type, for example a gear pump. The intake side of the pump communicates with a pipe 41 connected to the bottom of a liquid supply tank 42 into the top of which extends the discharge end of a drain pipe 43 the intake end of which is connected with the well 18 via a fitting 44 extending a short distance up through the bottom well plate 18e. The projection of the fitting 44 into the well to a distance of about /8 inch above the plate 18e forms a trap to inhibit the passage of foreign particles or other solid sediment and impurities into the tank 42. Associated with the tank 42 is a reservoir 45, the flow of liquid from the reservoir to the supply tank being achieved through a pipe 46 controlled by a valve 47 the extent of opening of which is controlled bya float 48 adapted to sense the level of the liquid in the supply tank 42.

As hereinbefore intimated, in accordance with one aspect of the present invention the apparatus shown in FIGS. 1 and 2 is particularly adapted for use in the application of a plasticizer to a moving band of filamentary material, e.g. cigarette tow. To provide a passageway for such materials, there are arranged in the side walls 12 and 13 of the housing 11 a pair of parallel, coextensive, preferably

rectangular openings

49 and 50. A bar 51 of circular cross-section is mounted, through the intermediary of a radial slot 5111, on that part of the wall 12 defining the lower edge of the opening 49 and is secured to the said wall by means of one or more set screws 5112. Similarly, an elongated bar 52 of circular or annular cross-section is mounted, through the intermediary of a radial slot 52a, on that part of the wall 13 defining the lower edge of the opening 50. Secured to that part of the wall 12 defining the upper edge of the opening 49, by means of a slot 53a and set screws 53b, is an elongated bar 53 of circular cross-section to one side of which adjacent to the opposite ends are welded two transversely extending circular bars 54. In like manner, a bar 55 having a slot 55a is secured by set screws 55b to that part of the wall 13 defining the upper edge of the opening 50, and to this bar at one side adjacent the opposite ends thereof are welded two transversely extending circular bars 56. The arrangement is such that the spacings between the bars 54 and between the bars 55 are slightly less than the lengths of the

respective openings

49 and 50. Thus, it will be seen that the various rods or members 51 to 56 provide rounded edges for the sides of the

openings

49 and 50 so as to prevent any snagging of the filamentary material passing therethrough. Since the opening 49 defines the inlet to the housing 11, the bars 54 are located exteriorly of the housing, while at the outlet opening 50 the bars 56 are located within the housing. The purpose of the smaller size of the bar 52 will be more fully explained presently.

As clearly shown in FIGS. 1 and 2, positioned interiorly of the housing 11 are two pairs of battles 57-58 and 5960 essentially constituted by fiat plates. The baflles 57 and 53 are welded at their upper ends to the ceiling section 19a of the housing 11, and the

battles

59 and 69 to the ceiling section 1%. The respective bafiles are bent upwardly at their lowermost ends to form troughs or

channels

57a, 58a, 59a, and 60a. The arrangement is such that the troughs of each pair slope downwardly in opposite directions, for example, the troughs 57a and 60:: toward the front wall 14 of the housing, and the troughs 53a and 59a toward the rear wall 15 of the housing. The function of these baffles will also be more fully explained presently.

Referring to FIG. 2, it will be seen that the front wall 14 of the housing 11 is provided with a relatively large opening 61 which is normally closed by a door 62 and may be opened to provide access to the interior of the housing for repairs, servicing, etc. Opposite the opening 61, the rear wall 15 of the housing is provided with an opening 63 which is covered by a transparent glass or plastic window 64 to permit inspection of the interior of the housing when the same is being used.

Specifically, if the apparatus 10 is to be employed in applying a plasticizer to a cigarette tow, the liquid in the tank 42 and reservoir 45 is composed of any suitable plasticizer composition, such as triacetin, dibutyl phthalate, methyl phthalyl ethyl glycoiate, or the like. Since the plasticizer must be applied uniformly to the filamentary tow over the entire expanse thereof as well as throughout its entire thickness, the tow is usually passed through a banding jet (not shown) or through a set of grooved towopening rolls (not shown) prior to being fed into the applicator chamber defined by the housing 11. Once the tow has been so opened, it is drawn through the

openings

49 and 50, as indicated by the arrow A, at a predetermined speed between about 50 and meters per minute. At the same time, the disc 20 is rotated by the motor 31 at a speed between about 1,000 and 10,000 revolutions per minute, while the liquid plasticizer is fed by the pump 40 at a rate of about to 300 grams per minute through the pipe 39, pipe 35 and nozzle structure 38 into the interior channel 26 of the disc defined between the flange 24 and the back plate 21. Due to the rotation of the disc, therefore, the liquid plasticizer is centrifugally forced out of and thrown away from the disc through the orifices 23 in the form of a sheet of fluid droplets disposed essentially in a plane which is perpendicular to the axis of rotation of thedisc and thus to the path of movement of the tow band. The rate of feed of the plasticizer into the disc, the speed of linear movement of the tow band, and the speed of rotation of the disc are so predetermined in relation to one another that some of those of the plasticizer droplets which are expelled upwardly out of the confines of the well 13 impinge against the bottom of the tow band, while others penetrate through the tow due to the latter having been previously opened. As a result, not only are the filaments located in the bottom and inner regions of the tow band coated with plasticizer, but the uppermost filaments are also so coated since some of those droplets which have sufficient energy to travel entirely through and upwardly beyond the top surface of the band thereafter fall back down onto the top surface of the band. In this manner, the plasticizer is applied uniformly to all of the filaments in the band.

The foregoing is diagrammatically illustrated in FIG. 6, wherein the filamentary material or tow band is designated by the reference character M, the droplets of liquid plasticizer by the reference character P, and the spraying disc by the reference character D (since this disc need not be the disc of FIGS. 1 and 2 but may have a different structure as will presently be described).

The use of the plasticizer applicator as herein described leads to a number of considerable advantages over heretofore known systems and techniques. The slanting of the ceiling of the housing 11 effectively ensures that any droplets of plasticizer which impinge against the ceiling flow along the ceiling sections 19:: and 19b to the bafiies 57 to 60 and then down along the latter and the troughs 57a to dim, from which the plasticizer drips onto the floor sections 16a and 17a. The slanting of the latter leads the so collected plasticizer to the well 18 from which it is returned to the supply tank 42 via the fitting 44 and drain pipe 43. Thus, the possibility of any plasticizer collecting on the ceiling centrally of the housing and dripping down therefrom onto the tow band is completely eliminated. At the same time, the bafiles serve as means which tend to block such excess plasticizer from running all the way down along the ceiling sections 190 to 19b to the side walls 12 and 13 and thence to the

openings

49 and 50 from which the plasticizer might drip in an unwanted and uncontrolled manner onto the tow passing through those openings. However, even if some plasticizer should reach the walls 12 and 13, the

slots

53a and 55a in the bars 53 and 55 are made so wide that they function as gutters or traps and prevent the plasticizer from reaching the tow band. The bafiies 57 to 60 further serve to condense excess droplets which do not reach the ceiling or fall back onto the tow, and thereby prevent the passage through the slot 50 of such droplets which could otherwise happen due to the air currents generated by the tow moving through the housing.

Another advantage attending the present invention is that all plasticizer not applied to the tow band is returned to the tank 42 and may be recycled by the metering pump 40 into the disc 20 for further use. The apparatus according to this invention thus employs a closed plasticizer feed system which admits of no losses of plasticizer from the system, contrary to those of the known plasticizer applying devices which involve a pressure-type spraying of the plasticizer that inevitably leads to quantities of the plasticizer being exhausted from the applicator chamber with the contaminated atmosphere thereof. Still further, inasmuch as the tow hand does not come in contact with the peripheral surface of the disc 20, there is no drag exerted on the band during the plasticizer applying operation, whereby the movement of the band through the applicator chamber remains uniform, which also aids in achieving a greater uniformity of plasticizer application. By the same token, the rounding of the edges of the

openings

49 and 50 as described also leads to a minimization of drag should the tow band contact those edges, and the use of the small diameter bar 52 at the exit opening 50 further enlarges the latter and effectively ensures that the plasticized band Will not contact the edges of the said opening, whereby the possibility of plasticizer being wiped or rubbed off the tow band is prevented.

It is, of course, possible in accordance with the present invention to employ discs the construction of which differs somewhat from that of the disc 20 shown in FIGS. 1 and 2. In accordance with one aspect of the present invention, as shown in FIG. 3, such a modified disc 20a resembles the disc 20 in that it is substantially cup-shaped and provided with circumferentially spaced radial orifices 23 in its peripheral side wall 22'. The front of the disc 20a, however, is substantially closed by a plate 65 which is removably fastened to the inwardly directed flange 66, for example by means of screws 66a and is provided with a central inlet opening 67. The disc 20a is most preferably employed in conjunction with a nozzle 68 (indicated in phantom outline in FIG. 3) arranged within the well 18 so as to direct a stream of the liquid plasticizer horizontally through the opening 67 and into the interior of the disc 20a. The rotation of the disc is effective centrifugally to move the liquid hitting the back plate of the disc radially outwardly of the latter and toward as Well as through the orifices 23'.

In accordance with another aspect of the present invention, the modified disc 20b is of the type shown in FIGS. 4 and 5. This disc comprises a solid and imperforate body 69 on the front face of which are milled or otherwise formed a plurality of radially extending grooves 70 which increase in depth from the center of the disc toward the periphery thereof. These grooves are substantially V-shaped in cross-section when viewed radially of the disc 2%, and the ridges 70a separating the grooves are substantially triangular in cross-section when viewed in the same sense. This disc too must be used with a nozzle 68 (indicated in phantom outline in FIG. 4) positioned substantially horizontally to direct the stream of liquid plasticizer against the center of the disc. The rotation of the disc then becomes effective to cause the liquid to move under the influence of centrifugal force along the various grooves and to leave the disc surface at the outermost and deepest ends of the grooves. Each of the discs 20a and 2% may, therefore, be the disc D illustrated schematically in FIG. 6.

It will be understood that although the practice of the present invention has up to this point been illustrated and described as entailing the use of only a single disc, more than one such disc may be employed. This is illustrated diagrammatically in FIGS. 7 and 8. FIG. 7 illustrates a pair of discs D which are disposed in side by side relation, rotatable about parallel horizontal axes, and operative to spray liquid droplets P, in the manner hereinbefore set forth, on a band of filamentary material M passing thereabove. FIG. 8 illustrates a pair of similarly arranged side by side discs D operative to spray the liquid onto a band of filamentary material passing therebetween.

The arrangement shown in FIG. 8 is especially advantageous when the band of material M to be sprayed, is relatively dense, or has been previously compacted, or is non-porous or impervious, to such a degree as to prevent the droplets ejected from one disc from passing through the material in the manner illustrated in FIGS. 6 and 7. Thus, the arrangement of FIG. 8 is found to be of great utility in spraying liquid materials, e.g. plastics or the like, onto such bodies as rope, wires, plates, webs and the like which are to be coated with such material on their outer surfaces. It will further be understood that the discs need not rotate in opposite directions as shown in FIGS. 7 and 8, but could rotate in' the same direction. Moreover, the axes of the discs need not be disposed in the same horizontal plane as shown in FIGS. 7 and 8, but could be in a vertical plane or in a plane oriented at an angle to the vertical, and by the same token the material to which the liquid is to be applied need not move in a strictly horizontal path but could move in a vertical or slanted path. Preferably, if two (or even more) discs are employed together, the planes of the discs are somewhat offset relative to one another, to ensure not only that the discs do not spray liquid on one another but also that the respective sheets of droplets do not interfere with one another (as they might if the droplets from one disc hit oppositely moving droplets from another disc). In any multiple disc arrangement, of course, each disc is preferably associated with its own individual liquid-feeding system and nozzle.

The discs 20, 20a and 20b of the present invention may also be employed in the performance of processes which require the spraying of liquid apart from the application of such liquid to any given surface or material. Merely by way of example, in accordance with one aspect of the present invention these discs may be employed as spinning devices in the manufacture of synthetic fibers by centrifugal extrusion. To this end the nozzle is employed to direct solvated, molten or solid fiber forming materials in metered quantities at the disc. Extrusion spinning discs of this type may be employed to form both staple fibers and continuous filaments, and may also be employed to produce an extrusion twisted yarn composed of such filaments.

In any applicator system employing one or more of the liquid spraying discs of the aforesaid types, it is further possible to stop and start the apparatus almost instantaneously. This can be achieved, even though the disc or discs remain in constant rotation, by interrupting or starting the .fiow of liquid to the nozzle structure 38 (or 68) by stopping or starting the pump 40. In a system of this type, whenever the liquid feed is interrupted, the scattering of droplets of liquid from the disc or discs stops with in a matter of seconds.

The principle of the present invention will be more fully understood from the following examples.

Example I A cigarette tow composed of 15,600 cellulose acetate continuous filaments having a total denier of 50,000 was passed through an applicator chamber, constructed substantially in the form of the housing 11 shown in FIGS. 1 and 2, at a linear speed of 150 feet per minute. The disc was constructed in the manner of the disc 20 shown in FIGS. 1 and 2, had a diameter of 4% inches, and included 16 radial orifices, each with a diameter of inch, peripherally spaced thereabout. The disc was rotated at a speed of 2,700 revolutions per minute, and liquid plasticizer, in this case triacetin, was pumped to the disc at a rate of 140 grams per minute. It was found that the tow leaving the applicator chamber was uniformly coated with the plasticizer at all points and that approximately 20% of the total plasticizer fed to the disc was applied to the tow. The remaining 80% of the plasticizer was returned to the supply tank for recirculation.

Example II A 5.0 denier per filament cigarette tow having a total denier of 52,000 was passed through the applicator chamber shown in FIGS. 1 and 2 at a linear speed of 150 feet per minute. The disc 20 had a diameter of 4% inches and included 24 radial orifices, each with a diameter of A.; inch, peripherally spaced thereabout. The disc was rotated at a speed of 3,550 revolutions per minute, and triacetin was pumped to the disc at the same rate as in Example I. The add-on of the plasticizer was 8%. An extremely uniform application of plasticizer resulted, and cigaretter filters produced from this tow were of excellent quality.

8 Example III A 3.2 denier per filament cigarette tow with a total denier of 50,000 was fed at a linear speed of 300 feet per minute through an applicator chamber employing a disc constructed as in Example I. The disc was rotated-at 3,550 revolutions per minute. The plasticizer in this case was triacetin with a blue tint added. The add-on of plasticizer was about 7%, and the application was achieved with great uniformity, permitting the coated tow to be used in making colored filter rods.

Although the preceding description has been directed essentially to the spraying of plasticizer onto filamentary material such as cigarette tow, it will be clear to those skilled in the art that the present invention is applicable to the application of a variety of finishes other than plas ticizers, e.g. lubricants and anti-static agents, to such materials. Lubricants which lend themselves to the processes of the present invention are, for example, light mineral oil, olive oil, diethylene glycol and the like. Antistatic agents which may be applied in this manner are such substances as mixtures of diethylene glycol, water and magnesium chloride in predetermined proportions, oleates and stearates of triethanolamine, and the like. Other additives designed to affect the taste, appearance and related properties of cigarette filters could also be applied by means of the apparatus 10, and the liquid compositions may be colored or colorless. The use of colors may, of course, be of particular importance in operations where impervious bodies are to be coated, for example wires or flat plates.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention what we desire to secure by Letters Patent is:

1. A process of applying a liquid to a filamentary material comprising feedin said liquid to and into contact with an inner portion of a rotatable disc member provided with a plurality of peripherally spaced outlets disposed radially about said disc member, concurrently rotating said disc member to cause said liquid to flow under the influence of centrifugal force and to leave said disc member in the form of a substantially plane sheet of droplets, and concomitantly advancing said filamentary material past said rotating disc member along a path substantially transverse to the plane of and transecting sa d sheet of droplets, the rotational speed of said disc member and the rate of feed of said liquid to said disc member being predetermined to ensure that a portion of said droplets penetrate entirely through said band of filamentary material.

2. The process of claim 1, wherein said disc member is rotated about a non-vertical axis, and said band of filamentary material is advanced past said disc member above the latter, whereby those of the upwardly directed droplets which pass through said band of filamentary material thereafter fall back onto the upper surface of the latter.

3. The process of claim 2, wherein said band of filamentary material comprises an opened cigarette filter tow, and said liquid comprises a plasticizer.

4. The process of claim 3, wherein said tow is composed of continuous cellulose acetate filaments, and said plasticizer comprises triacetin.

5. The process of claim 3, wherein the rate of advance of said tow past said disc ranges from about 50 to about meters per minute, the rate of feed of said plasticizer to said disc ranges from about 10 to about 300 grams per minute, and the rotational speed of said disc ranges from about 1,000 to about 10,000 revolutions per minute.

6. The process of applying a liquid to a filamentary material, comprising the steps of feeding said liquid to and into contact with the inner portions of a plurality of laterally offset rotatable disc members each provided with a plurality of radial passageways, concurrently rotating said disc members to cause the associated quantities of said liquid to flow under the influence of centrifugal force along the respective passageways and to leave said disc members in the form of respective substantially plane sheets of droplets, and concomitantly advancing said filamentary material past said rotating disc members along a path substantially transverse to the plane of and transecting said sheets of droplets, said disc members being rotated about substantially parallel axes and said base member being advanced past said disc members and between the latter whereby said liquid is applied simultaneously to the opposite surfaces of said base member, the rotational speed of said disc members and the rate of feed of said liquid to said disc members being predetermined to ensure that a portion of said droplets penetrate entirely through said band of filamentary material.

7. The process of claim 6, wherein said disc members are rotated about non-vertical axes, and said filamentary material comprises a band of filamentary material which is advanced past said disc members above the latter, whereby those of the upwardly directed droplets which pass through said band of filamentary material thereafter fall back onto the upper surface of the same.

8. Apparatus for applying a liquid material to a filamentary material, comprising a housing, said housing being provided at two opposed locations with a pair of openings defining a generally horizontal path therebetween for said filamentary material, at least one rotatable disc member located in said housing beneath said filamentary path and disposed in a plane of rotation transecting said path, the normal distance from said horizontal path to the axis of rotation of said disc member being somewhat greater than the radial dimension of said disc member, means for feeding said liquid material to and into contact with an inner portion of said disc member, said disc member being provided with a plurality of peripherally spaced outlets disposed circumferentially of said disc member, means operatively connected to said disc member for rotating the same at a speed sufficiently high to cause said liquid material to flow under the infiu ence of centrifugal force through said outlets and to leave said disc member in the form of a substantially plane sheet of droplets, and means for concomitantly advancing said filamentary material along said horizontal path above said rotating disc member, said path being substantially transverse to the plane of and transecting said sheet of droplets, the rotational speed of said disc member, the rate of advance of said filamentary material past said disc member, the rate of feed of said liquid material to said disc member, and the speed of rotation of the disc member being selectively adjusted whereby a portion of said droplets penetrate entirely through said band of filamentary material and thereafter fall back onto the upper surface of said band of filamentary material.

9. Apparatus according to claim 8, said means for feeding said liquid mate-rial to said disc member comprising a nozzle member positioned to extend into said disc member and to discharge said liquid material therein, and pump means communicating with said nozzle member for feeding said liquid material to the latter at a predetermined fiow rate.

10. Apparatus according to claim 8, said disc member comprising a substantially cup-shaped structure having an imperforate back plate, a peripheral side wall extending from one face of said back plate, and an annular flange extending from the outermost end of said side wall inwardly of said disc member, said side wall being provided with a plurality of narrow bores which constitute said outlets and communicate at their inner ends with the annular channel defined between said back plate and said annular flange.

11. Apparatus according to claim 8, said disc member comprising a substantially solid and imperforate plate, said plate having provided in its front face a plurality of radially extending grooves each of which is narrowest and shallowest at the center or" said plate and widens and deepens gradually toward the outer periphery of sa d plate, said grooves constituting said outlets.

12. The apparatus of claim 8, wherein said disc memher is mounted in a plane of rotation substantially perpendicular to said filamentary path.

13. The apparatus of claim 12, wherein said orifices have a diameter ranging from about & to about 5 inch.

14. The apparatus of claim 12, wherein said housing comprises vertical side walls, vertical front and rear walls, a floor and a ceiling, said fioor comprising a pair of sections extending toward one another from the lowermost edges of said side walls at a relatively gentle downward slope and terminating at a predetermined distance from one another essentially medially of the housing thereby leaving an opening in Which is defined a well, said ceiling being closed and comprising a pair of sections extending toward one another at relatively steep slopes from the uppermost edges of said side walls.

15. The apparatus of claim 14, also comprising at least one pair of battles constituted by flat plates depending from the ceiling of said housing, said plates terminating above said filamentary path and being bent upwardly at their lowermost ends to form troughs which slope downwardly in opposite directions toward opposing walls of said housing.

References Cited UNITED STATES PATENTS Re. 24,923 1/1961 Hoff 118-325 X 1,022,956 4/1912 Lengerke et al. 239-222 X 1,946,831 2/1934 Bracewell 117-104 X 2,584,973 2/ 1952 Andermatt 239-222.11 2,643,636 6/1953 Bauer 118-316 2,775,792 1/1957 'Beardsell et al. 118-316 X 2,850,322 9/1958 Ingram 239-222 2,865,324 12/1958- Stein 117-1053 X 2,986,338 5/1961 Foster 239-222 3,133,702 5/1964 Stelche 239-214 X 3,176,650 4/1965 Woellner 118-325 X ALFRED L. LEAVI'IT, Primary Examiner.

J. H. NEWSOME, Assistant Examiner.